I'm playing mostly 360 mode and going:
1) Town stage -> Get up to 1000 on Item Counter by the end
2) Graveyard -> Activate mid-way through and then try to recharge my item counter to 1000 on the big house at the end
3) Forest -> Activate Power-up mode at the beginning, score some points and then try to do the bomb recharge trick on the big vine plants (still not getting it consistently). Then I activate on the last part of the boss' phase and get like +2000 on the counter.
4) Volcano -> Start off with +2000 and try to grind like crazy. Not sure if you can recharge the item counter on this stage.
5) Lakeside ->Score ok and try to have 1000 at the end
6) Swamp stage -> Don't have a really good strategy here
Then if I haven't died too many times I might try the gorge before the castle.
I've only been going for survival at the moment. My route will change once I start scoring. I do have over 80,000,000 with Rosa though.
Forest(2), Swamp(2), Town(3), Graveyard(3), Lake Shore(3), Volcano(3)
Once I start seriously going for score, Volcano will be second as I hate that stage in Death Mode which I currently avoid, plus you want to know whether to restart early if you mess up the rock milking.
For the 1.1s, I go Town, Graveyard, Forest, Swamp, Lake Shore, Volcano.
Currently Playing: Infinite Undiscovery, Deathsmiles, Mushihimesama Futari, Touhou series
Yeah the Forest is such a goldmine that I try to avoid doing it on the first level. Sometimes I'll switch up and do Lakeside first. There's that really nice route which gets you two cakes and a bomb that starts at Lakeside.